Improvement in tempering and refining steel



UNITED STATES PATENT OFFICE.

ALEXANDER H. SIEGFRIED, OF SOUTH BEND, INDIANA, ASSIGNOR TO THE STEEL-REFINING-AND-TEMPERING COMPANY, OF BOSTON, MASS.

IMPROVEMENT IN TEMPERING AND REFINING STEEL.

Specification forming part of Letters Patent No. 129,432, dated July 16, 1872.

To all whom it may concern:

Be it known that I, ALEXANDER H. SIEG- FRIED, of South Bend, in the county of St. Joseph and State of Indiana, have invented a new and useful Improvement in the Art of Tempering and Refining Steel; and I do here by declare that the following is a full, clear, and exact description of the same.

On the 31st day of January, A. D. 1871, Letters Patent of the United States issued to George B. Garman for an improved mode of tempering steel, and on the 11th day of April, A. D. 187 1, other Letters Patent of the United States issued to me for an improved process for tempering and refining steel. In working these processes I have ascertained that certain modifications thereof are important, as giving better results and reducing the cost of working the process.

My improvements consist in combining these two processes in the process of manufacture, and in modifying the proportions of the mixtures mentioned in said last-named Letters Patent to provide against changes in relative quantities of the ingredients, both dry and in solution, by the actionof heat.

To enable those skilled in the art to work my improved process in the best form now known to me, I will proceed to describe the same.

I first heat the steel to a cherry-red in a clean smiths fire, and then cover tile -steel with chloride of sodium, (common salt,) purifying the fire also by throwing in salt. I work the steel in this condition, and while subjected to this treatment, until it is brought into nearly its finished form. I then substitute for the salt a compound composed of the following ingredients and in about the following proportions: One part, by weight, of each of the following substances: chloride of sodium, sulphate of copper, sal-ammoniac, and sal-soda, together with one-half part, by weight, of pure 5555mm" f sulphate'of copper, one ounce a'iidahalffofmitrate of potassa, one ounce and of chloride..0f, s0dium,.sixounces. These quantities and proportions are stated as being what I regard as practically the best, but it is manifest that they may be slightly changed without departing from the principle of my invention.

By using the salt in the beginning of the process instead of the compound mentioned in my said Letters Patent of April 11th, A. D. 1871, the process can be more economically conducted and with equally good results, and by using the compound mentioned at the next step in the operation a better result will be reached than can be obtained by the process set forth in the said Letters Patent of January 31, 1871.

What I claim as my improvement in the art of refining and tempering steel, and desire to secure by Letters Patent, is-

The successive processes or steps of the process, with the use of the materials or their equivalents, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

A. H. SIEGFBIED.

Witnesses:

D. P; HOLLOWAY, 'B. Enw. J. EILs. 

